FireAid is projected to collect $100 million in donations to those affected by the Los Angeles fires Billie Joe Armstrong was a Billie Eilish fan well before they shared the stage at FireAid. Following the benefit concert at the Kia Forum on Thursday,

Billie Joe Armstrong says it was an "honor" to perform with "pretty awesome young lady" Billie Eilish. The 52-year-old rocker's band Green Day duetted with the 'Birds of a Feather' hitmaker on their 2009 track ‘Last Night On Earth’ at the FireAid benefit concert for victims of the Los Angeles wildfires at the Kia Forum on January 30.

LOS ANGELES (Reuters) - Billie Eilish made a surprise appearance on stage with Green Day on Thursday to kick off one of two star-studded concerts in Los Angeles put together to raise funds for people affected by deadly wildfires in California this month.